In order to be able to manufacture ceramic products, they have to be fired in a kiln. For importing and exporting from the oven, these ceramic products are preferably supported on a device, which can be moved into the oven and removed again. In the state of the art, respective kiln carts are known for this purpose, comprising fire resistant superstructures (kiln cart superstructures) made form support assemblies, in which respective holders or support systems for ceramic products or the kiln run in general are formed from several supports and support carriers, like carrier beams, cross beams, large plates or similar.
According to a known embodiment, the supports are provided with window openings, in which carrier beams can be received. Typically the supports are provided as rectangular tubes, so that the window openings are provided in two opposite side walls of the rectangular tubes. When inserting a carrier beam, which is typically also provided as a rectangular tube, thus two support locations of the carrier beam are created in the support, thus in one respective side wall. This leads to the disadvantage that, in case of imprecisions or deformations of the supports, or carrier beams, no equal load is created in the supports, but the carrier beam possibly only rests in one side wall, and in the extreme, even punctiform contact locations are created. This leads to a one-sided loading of the support with the respective induction of moments, which are problematic, in particular, with the typically used material for supports, carrier beams, etc., which has to be suitable for the high firing temperatures of the ceramic kiln run. Typically ceramic materials, e.g. Al2O3, RSiC, SiSiC, NSiC or Mullite, are used for the superstructure of the kin cart, which are known to be sensitive with respect to tension—and/or bending loads.
It is disadvantageous, in particular that, in case of horizontally non aligned window openings and carrier beams, punctiform contact locations are created in the side walls, which creates the risk of chipping off ceramic material from the supports and carrier beams. Through elastic bending of the carrier beams, when they are loaded with ceramic kiln run, the stress peaks at the support locations of the carrier beams on the side walls are even increased.
An additional reinforcement of the load peaks can also be created by the fact that at the typical firing temperatures of over 1000° C., due to the thermal expansion of the materials, motions between the particular components of the support arrangements, thus also between the carrier beams and the supports, inevitably occur. Due to the surface support of the carrier beams on two supports in the side walls, large amounts of friction occur between the carrier beam and the support. Due to this large amount of friction, the thermal expansion of the carrier beams cannot be relieved in a defined manner, whereby the transfer of high lateral forces becomes possible.
Various methods were suggested, in order to eliminate these disadvantages. E.g. through the insertion of carrier plates into the window openings, wherein the carrier plates can also be provided cylindrical or convex, defined contact areas between the side walls and the carrier beams shall be assured. Furthermore, in case of a possible tipping of the carrier beams, chipping on the side walls of the window openings shall be avoided. The Patent document DE 203 05 182 U1 provides e.g. to support the carrier beams on differently shaped support bodies, which are mounted in the support, perpendicular to the window openings. These support bodies are thereby inserted into the support, or tied to the support, loosely but precisely fitting. Thereby, the high amount of friction of a line shaped support between carrier beam and support body is maintained, and the thermal expansion between carrier beams and supports during heating and cooling cannot be relieved in a defined manner.
Thus it is the object of the present invention to provide a device for holding and supporting or stacking and transporting kiln run, in particular, kiln run for firing ceramic products, which avoids the advantages of the above described state of the art. In particular, a device shall be provided, which relieves thermal expansions of the carrier beams in a defined and reliable manner. This relief shall also occur, when heavy ceramic products, e.g. washbowls and toilets, are supported on the device. Furthermore, this device shall be simple to manufacture.